The hallmark of grace is an obedient heart. Again, we must be clear: obedience does not produce or maintain salvation, but it is the inevitable characteristic of those who are saved. The desire to know and obey God's truth is one of the surest marks of genuine salvation. Jesus made it clear that those who obey His word are the true believers (John 8:31; 14:21, 23-24; 15:10). Slaves of sin--unbelievers--are free from righteousness (Romans 6:20). Christians, on the other hand, are free from sin and enslaved to God through faith in Jesus Christ (v. 22). The inevitable benefit is sanctification, and the ultimate outcome is eternal life (v. 22). This promise sums up the whole point of Roman 6: God not only frees us from sin's penalty (justification), but He frees us from sin's tyranny as well (sanctification).